Estimation and improvement of multi-path error of IGS signal based on digital filtering technique.

This article focuses on addressing the multipath error problem in International GNSS Service (IGS) signals, which affects positioning accuracy and signal stability due to signal reflections during propagation. It proposes an improved multipath error estimation and correction method based on digital filtering techniques, particularly combining Discrete Fourier Transform (DFT) and Finite Impulse Response (FIR) filters, to enhance signal quality. Experimental results from five tracking stations across diverse terrains in China demonstrate an average root mean square error reduction of 38.4%, with notable improvements in mountainous and urban environments, especially for low-frequency multipath interference below 1 Hz. The study provides theoretical and practical insights for optimizing digital filter design and suggests future work on adaptive filtering and broader GNSS applications to improve reliability under varied environmental conditions.